Encode and decode integers in the LEB128 format.
Provides functions to encode and decode integers to streams and arrays using the signed and unsigned LEB128 format.
All of the functions expects to operate on integer values, streams and
vectors with element types (unsigned-byte 8).
(encode-signed integer &optional output start)
(encode-unsigned integer &optional output start)
Return two values, the encoded integer and the length of the encoding.
If OUTPUT is a stream then write the encoded INTEGER to it, preceding
the encoding with START number of zero bytes. Return OUTPUT and the
number of bytes written.
If OUTPUT is NIL then create a (vector (unsigned-byte 8)) and encode
INTEGER into it. If START is given then precede the encoding with
START number of zero bytes. Return the vector, and its length.
If OUTPUT is a (vector (unsigned-byte 8)) then encode INTEGER into it,
beginning at START. Return OUTPUT and the end index of the encoding.
(decode-signed input &optional start)
(decode-unsigned input &optional start)
Return two values, the decoded integer and the length of its encoding.
Return an integer decoded from INPUT beginning at START,
and the end index of the encoded value.
INPUT may be a stream or a (vector (unsigned-byte 8)).
If INPUT is a stream then START number of bytes is consumed and
discarded before the integer is decoded. The end index returned will
be the number of bytes consumed in total.
(signed-length integer)
(unsigned-length integer)
Return the number of bytes needed to encode INTEGER.
Copyright (c) 2021 Roy Arne Gangstad.
Licensed under the Apache License, Version 2.0.